I have long been interested in classifications of people, in how they affect the people classified, and how the affects on the people in turn change the classifications. We think of many kinds of people as objects of scientific inquiry. Sometimes to control them, as prostitutes, sometimes to help them, as potential suicides. Sometimes to organise and help, but at the same time keep ourselves safe, as the poor or the homeless. Sometimes to change them for their own good and the good of the public, as the obese. Sometimes just to admire, to understand, to encourage and perhaps even to emulate, as (sometimes) geniuses. We think of these kinds of people as definite classes defined by definite properties. As we get to know more about these properties, we will be able to control, help, change, or emulate them better.

But it's not quite like that. They are moving targets because our investigations interact with them, and change them. And since they are changed, they are not quite the same kind of people as before. The target has moved. I call this the ‘looping effect'. Sometimes, our sciences create kinds of people that in a certain sense did not exist before. I call this ‘making up people'. What sciences? The ones I shall call the human sciences, which, thus understood, include many social sciences, psychology, psychiatry and, speaking loosely, a good deal of clinical medicine. I am only pointing, for not only is my definition vague, but specific sciences should never be defined except for administrative and educational purposes. Living sciences are always crossing borders and borrowing from each other.

The engines used in these sciences are engines of discovery but also engines for making up people. Statistical analysis of classes of people is a fundamental engine. We constantly try to medicalise: doctors tried to medicalise suicide as early as the 1830s. The brains of suicides were dissected to find the hidden cause. More generally, we try to biologise, to recognise a biological foundation for the problems that beset a class of people. More recently, we have hoped to geneticise as much as possible. Thus obesity, once regarded as a problem of incontinence, or weakness of the will, becomes the province of medicine, then of biology, and at present we search for inherited genetic tendencies. A similar story can be told in the search for the criminal personality.

These reflections on the classification of people are a species of nominalism. But traditional nominalism is static. Mine is dynamic; I am interested in how names interact with the named. The first dynamic nominalist may have been Nietzsche. An aphorism in The Gay Science begins: ‘There is something that causes me the greatest difficulty, and continues to do so without relief: unspeakably more depends on what things are called than on what they are.' It ends: ‘Creating new names and assessments and apparent truths is enough to create new “things”.' Making up people would be a special case of this phenomenon.

Around 1970, there arose a few paradigm cases of strange behaviour similar to phenomena discussed a century earlier and largely forgotten. A few psychiatrists began to diagnose multiple personality. It was rather sensational. More and more unhappy people started manifesting these symptoms. At first they had the symptoms they were expected to have, but then they became more and more bizarre. First, a person had two or three personalities. Within a decade the mean number was 17. This fed back into the diagnoses, and became part of the standard set of symptoms. It became part of the therapy to elicit more and more alters. Psychiatrists cast around for causes, and created a primitive, easily understood pseudo-Freudian aetiology of early sexual abuse, coupled with repressed memories. Knowing this was the cause, the patients obligingly retrieved the memories. More than that, this became a way to be a person. In 1986, I wrote that there could never be ‘split' bars, analogous to gay bars. In 1991 I went to my first split bar.

This story can be placed in a five-part framework. We have
(a) a classification, multiple personality, associated with what at the time was called a ‘disorder'. This kind of person is now a moving target. We have
(b) the people, those I call ‘unhappy', ‘unable to cope', or whatever relatively non-judgmental term you might prefer. There are
(c) institutions, which include clinics, annual meetings of the International Society for the Study of Multiple Personality and Dissociation, afternoon talkshows on television (Oprah Winfrey and Geraldo Rivera made a big thing of multiples, once upon a time), and weekend training programmes for therapists, some of which I attended. There is
(d) the knowledge: not justified true belief, once the mantra of analytic philosophers, but knowledge in Popper's sense of conjectural knowledge, and, more specifically, the presumptions that are taught, disseminated and refined within the context of the institutions. Especially the basic facts (not ‘so-called facts', or ‘facts' in scare-quotes): for example, that multiple personality is caused by early sexual abuse, that 5 per cent of the population suffer from it, and the like. There is expert knowledge, the knowledge of the professionals, and there is popular knowledge, shared by a significant part of the interested population. There was a time, partly thanks to those talkshows and other media, when ‘everyone' believed that multiple personality was caused by early sexual abuse. Finally, there are
(e) the experts or professionals who generate (d) the knowledge, judge its validity, and use it in their practice. They work within (c) institutions that guarantee their legitimacy, authenticity and status as experts. They study, try to help, or advise on the control of (b) the people who are (a) classified as of a given kind.